Scanning radiographic equipment differs from conventional radiography in that it employs a narrowly collimated beam of radiation, typically x-rays, formed into, for example, a pencil beam, a narrow fan beam, or a broad fan beam, rather than a broad area cone beam. The compact beam size allows the replacement of an image forming sheet of radiographic film, used with conventional radiographic equipment, with a small area array of electronic detector elements. Further, the scanning allows the collection of data over a much broader area than would be practical with a single x-ray cone beam. The electronic detector elements receiving the transmitted radiation produce electrical signals which may be discriminated by pulse height into various pulse height bins and counted or charge collected and converted to digital values by an analog-to-digital converter for the later development of an image or for other processing by computer equipment.